Timer



A. W. KAUFMAN.

TIMER. APPLICATION FILED APR.I5,1921.

1,41 1,787,. Patented Apr. 4,1922.

- III A? I A. W. KAUFMAN.

TIMER.

APPLICATION HLED APR. 15, I921.

1,411 1,787. atente Apr. 4, 1922.

2 $HEETSSHEET 2.

.ADAM W. KAUFMAN, OF MILWAUKEE, WISCONSIN.

TIMER.

specification of Iietters Patent. Patented Apr. 4, 1922.

Application filed April 15, 1921. Serial No. 461,629.

To all whom it may concern:

Be it known that I, ADAM N. KAUFMAN, a citizen of'the United States, andresident of Milwaukee, in the county of Milwaukee .and State ofWisconsin, have invented certain new and useful Improvements in Timers,and I do hereby declare that the following is a full, clear, and exactdescription thereof. 1

My intention refers to commutators known to the trade as timers, forcontrolling the ignitionspark of the internal combustion engines, and ithas for its object to provide a simple, economical, effective anddurable timer, wherein oiling is dis pensed' with and all wearing partscan be quickly replaced at nominal cost to thus render the life of thetimer indefinite.

Specific objects of my invention are: i To provide a. full floatingcontact tip embodying essentiallyatight coiled spring more clearlyillustrate details of construcsection that will sensitively respond to amake-and-break wiper, the coil section being capable of absorbing theyield, when coming in contact with its companion member,-throughout itsentire area whereby tendency to crystallize at a common point of yieldis avoided, the coils having the longitudinal and radial compensatingresiliency.

-To provide relatively rotative make-andbreak members, one of which isin the form of the "closely coiled spring adapted tozengage a wiper,whereby the associated contact'surfa'ces will insure a fat-spark, theSL1'Cl contactmg surfaces beingthus uniformly'polished andcleanedand'the wear reduced to a minimum withoutthe use of lubricants.

To provide means for quickly renewing the coil spring brush tips inconnection with a rigid holder, whereby the timer is main tained inperfect working condition at the replacement cost of a tip or tips.

With the-above and otherminor objects in view, the invention consists incertain peculiarities of construction and combination of parts, as arehereinafter set forth with reference to the accompanying drawings andsubsequently claimed.

In the drawings: i

Figure 1 represents a face viewof a timer embodying the features of myinvention, parts being broken away and in section to tion.

Figure 2 is a side elevation of the same, partly in section, asindicated by line 2-2 of Figure l.

Figure is a fragmentary enlarged detail view of a holder and brush tipmechanism made in accordance with my invention. Figure?) is a detailedview of another form of brushitip.

Figure 4 represents a face view of a timer illustrating a modified formof attaching the yieldablebrush tip to the holder, and a rotary wiper ofthe lip or lug type,

Figure 5 represents a side elevation of the same, partly in section, asindicated by line 5-5 of Figure 4.

Referring by characters to the drawings, 1 represents a rotary timershaft having securedthereto a wiper lug 2 of the radial cam type, itbeing understood that the device is shown particularly applicable toforward construction, and that the wiper lug or cam canreadily' beadjusted to thetimer shaft and locked in such adjustment by the standardFord clamping nut 3, which is in threaded union with the end of saidshaft.

A housing 4 is arranged concentrically about the shaft and adapted to beoscillated upon its bearing (not shown) whereby the spark may beadvanced or retarded. The

housingis provided, in this instance, with four radial openings,suitably fitted with washers 5 of insulating material through whichextends the-shank portion 6 of a series of holders. Each holder shank isprovided with an inner collar"? adapted to engage the lnner surface ofthe washer 5 and the shank is firmly held in place by a nut 5 inthreaded union with its corresponding threaded outer end, there being abinding nut 5 run upon the end of the holder shank for connecting theconductor wire. Extendingfrom the collar 7 of the holder 'is j athreaded coupling nipple 8,

which nippleisadapted to receive the outer end of a closelycoiled'section of spring 9, the same "constituting a brush tip. The

coils of the spring are approximately of the same pitch as the threadupon the coupling nipple, and hence, the brush tip can be readilyscrewed to position and held firmly by the coupling nipple, it beingunderstood that the free end of each coil spring is extendedin the pathof travel of the wiper lug, whereby make-and-break contact between therelatively rotative parts is effected.

As shown in Figures 1 and 2, the wiper cam is of the radial type, beinga section of a spiral. Hence, when the shaft 1 is rotated in thedirection of the arrow, the narrow end of the spiral shaft enters thefield of the coil spring brush tip and as the cam travels past the tip,it will gradually contact therewith and deflect it in a directionlongitu' dinal to the axis of the shaft. The coil spring will thus exerta yielding pressure upon the cam as it travels past the end coil of thetip to form a positive sliding contact, and insure a perfect electricalconnection, whereby an intensed spark will result. lVhen the heel of thecam passes the deflected brush tip, it will snap back to its normalrigid radial alignment. It will be observed that owing to this contact,the engaged parts will be wiped at each revolution of the shaft andfouling of the contacting point is thus avoided. Furthermore, owing tothe fact that the yielding coil spring engages the cam, at practicallyone point throughout its travel, and that this contact is compensatingin its nature, the liability to wear upon the rubbing parts is reducedto a minimum and said parts, as has been practically demonstrated, donot require oiling.

This is an important feature of my invention primarily, due to the factthat standard timers of this general type require constant care and oilfrom time to time; otherwise they will quickly deteriorate. Furthermore,in such structures, it has been found by actual test that the parts willwear, even though oiled from time to time. The relatively rotative partsof such standard. structures are generally of the cam shoe and rollertype. Under ordinary usage, the cam shoe of this type of make-and-breakmechanism will wear or roughen, and hence, when the roller travels overthe surface it will strike only upon high points, and thus develop animperfect spark. This imperfection of spark is also developed ininstances where the roller has flattened, due to constant engagement ofthe elements mentioned.

My device, as described, fully overcomes such objectionable features andthe problem, as I have solved it, relies primarily upon the use of acoiled spring brush tip having the full floating functions. wherebyshock in initial contact is absorbed and whereby the tendency tocrystallize at a given point is overcome, due to the fact that thespring yields uniformly throughout its free length and also transverselyto a certain extent, owing to the spring tension of the coils. Thistransverse yield is particularly developed in that form of my invention,as shown in Figures 1 and 2, which is the preferred form under certainconditions.

Obviously, the tips can readily be renewed or replaced by removal of theold and replacement, the operation being simply the insertion of asection about the nipple 8 and turn the same until it is firmly seatedupon the holder. Due to its screw threaded union, the detachable partwill not loosen under vibration, particularly as the coils of the springtip are slightly expanded when run upon the threaded coupling nipple. Itis obvious that the cost of renewal is nominal, under such conditions,and it can be effected by those not skilled in the art.

Hence, the life of the timer may be extended indefinitely by thissimple, adjustable arrangement of coil spring tips.

Referring now more particularly to Figures 4 and 5, the wiper cam 2 inthis instance is of the radial or fin type, and as best shown in Figure4, when the rounded end of the fin comes in contact with the freeloading end of the coil spring brush tip, said brush tip will bedeflected tangentially, and as the fin travels past the tip, it willproduce a rolling contact, the length of which depends upon the lapcontact space between the relatively movable parts. In thisexemplification of my invention, the outer end of the coil spring tip isfitted and secured into a cupped end of the holder shank, which cuppedend forms an extension 7 of the collar portion of said shank. Obviously,the coupling between the shank and coil spring can be effected by athreaded union of the internal type, or this union may be efi'ected bysolder or other convenient means, in which case for renewal purposes theentire holder would have to be replaced.

WVhile I have shown and described two forms of my invention, various sugestions as to details of construction might be used for carrying out theprimary object, which is to provide the coil spring brush tips that maybe renewed, if desired, and obviously, a timer may be arranged in somecases with a single rotatory brush tip, which tip would be adapted toengage a plurality of contact shoes carried by the timer housing, thissuggestion being merely a reversal of parts.

Figure 8 illustrates a fragment of a brush tip having a solid contacthead associated therewith, the head being secured by a shank which is inthreaded union with the end of the spiral coil. This cont-act shoe, insome instances, is used and materially increases the wear of thestructure.

I claim:

1.. As a new article of manufacture, a full floating brush tip forrotatory timers comprising a closely coiled section of spring wire,

and a holder therefor including a threaded section engageable with theends of the coil sprin tip 2. is a new article of manufacture, a fullfloating brush tip for rotatory timers comprising a closely coiledsection of spring wire, and a holder therefor including a threaded stemengageable with the ends of the coil spring tip, the coils of the springbeing of approximately the same pitch as the threaded stem. 1

3. As a new article of manufacture, a make-and-break mechanism forelectric circuits comprising relatively rotative members, one of whichincludes acoil spring section, the free end of which is adapted toengage the opposite member.

4. A timer comprising relatively rotative make-and-break members, one ofsaid members havin a yieldable'coil spring tip section, the ot er memberbeing in the form of a radial cam arranged to side-swipe the yieldabletip.

5. In a timer comprising a rotatory shaft, a cam lug carried thereby, ahousing adjustable about the shaft holders carried by the housing, andcoil spring tips extending from the holders adapted to have yieldingwiping engagement with the cam lug.

' 6. In a timer comprising a rotatory shaft, a cam lug carried thereby,a housing disposed concentrically with relation to the shaft and havinga plurality of apertures therein, holders fitted through the apertures,means for insulating the holders from the housing, radially disposedthreaded nipples extending from the holders and closely coiled springtips having their outer ends in threaded union with the nipples, thefree ends of the springs being arranged in the path of travel of the camlug, whereby successive wiping contacts are effected between these partsto successively make and break a series of circuits. 1

In testimony that I claim the foregoing I have hereunto set my hand atMilwaukee, in the county of Milwaukee and State of Wisconsin.

ADAM W. KAUFMAN.

